Antimicrobial composition and process for applying same



United States Patent 3,087,774 ANTIMICROBIAL COMPDSITION AND PROCESS OR APPLYING S 1 Meyer, Mendelsohn, New York, and Carl Horowitz,

Brooklyn, NY., assignors; by nisne assignments, to Yardney lnternational Corp New York,jN.Y., a corporation of New York 7 s v No Drawing. Filed'0et.-12, 1959, Ser. No. 845,663

12 Claims. (Cl. 8'--115.5)

Our present invention relates to atreatment' of fabrics and other materials with metallic compounds designed to impart antimicrobial properties to 'such'materials." s

In co-pending applications Ser. Nos. 738,967 and 760,857, filed by Meyer Mendelsohn on June 2, 1958, and September 15, 1958, respectively, both now abandoned, there has been disclosed a" treatment of" this character in whicha'zinc compound is causedito react on the fibers of a material to be treated, notably a cellulosic or proteinaceous material sotha't the zinc will firmly adhere to the fibers and exe'r'f'its" antimicrobial action even after repeated washings. More particularly, the treatmehtdis' closed in these pending applications involves theinimersion of the material'in an'aqueous bath at hight'eni peratures, the bath includingas its principal ingredients a chelating agent, a catalyst'su-ch as sodium acetate an'd optionally a detergent along with'za suitable zincfcompound such as zinc chloride: A fixingagent rich in amine groups, such as urea, is applied'to thernaterial' either" in the'sarne bath' or in a second treatment solution to help lock the zinc in place on the fibers.

Although the treatment just described is satisfactory with respect to both the safety of operation and the quantity of zinc fixed in the fibers, there are nevertheless occasions when a more rapid mode of application is desirable. Thus, immersion of fabrics and the like for a prolonged period (e.g. 10 minutes) in a hot aqueous solution, followed by the necessary drying operation, represents a process which is practical only in industrial plants and can not be conveniently carried out in the home, in small institutions or in a store where an on-the-spot antimicrobial treatment of goods is desirable.

It is, therefore, an object of our present invention to provide an improved process for supplying such compositions to fibrous materials at ordinary temperatures and without the use of a slow-drying aqueous medium; a related object is to provide a modified antimicrobial composition adapted to be so applied.

In accordance with this invention we dissolve a zinc salt, a chelating agent, a catalyst, an aminating agent and preferably a detergent and buffering agent in an organic solvent, advantageously, a low-boiling ketone. When this mixture is applied, e.g. by spraying, to the material to be treated, it is found that the zinc compound reacts with the other ingredients to form a complex which remains fixed to the fiber over prolonged periods of use and exhibits distinct zones of inhibition against micro-organisms even after many washings in hot or cold water. It is further found that the use of low-boiling ketones is so effective in carrying the zinc into the fiber that a given percentage of zinc fixed in the fabric is obtainable with a greatly reduced proportion of zinc compound in the starting material, as compared with the hot-water treatment of the co-pending applications referred to above.

3,087,774 Patented Apr. 30, 1963 The following is a list" of ketones found suitable for the process'of our invention, the lower-boiling ones being preferred because of their shorter drying time.

TABLE 1 Compound: Boilingpo'int C.)

Trifluoro acetone-" 21 Acet s 56 Hexafluoroacetyl acetone; 63-65 Z-bntanone (ethyl methyl) B buten Z-one (methyl vinyl) 81 Biacetyl acetone 88 Methyl isopropyl ketone; 94.3 Diethyl acetone 1 02 Methyl propyl ketone 102.3 Pinacolone H V 106 Methyl isobutyl ketone 116.8 Cyclohexanone' 156' The folowing proportions (by weight) have been found to give a satisfactory mixture:

TABLE 2 p 7 Parts Zinccompound nn 5 to 500 Aminating agent- 5 to 300 Chelating agent l to Catalyst l'to 350 Detergent 0 to Buffering agent 0 to 200 Volatile organic solvent 1000 As an optional ingredient there may be added to the above mixture a commercially available moth-proofing agent soluble in the same solvent, such as from 1 to 50 parts of an alkali aluminum fluoride, or silico fluoride.

The zinc compound is preferably zinc chloride but may also be zinc sulphate or zinc nitrate.

Detergent such as ethylene cycloimido l-alkyl (fatty acid) 2-hydroxy ethylene sodium alcoholate methylene sodium carboxylate 10 17.5 grams of the above mixture together with 17.5 grams of urea crystals are dissolved in 1000 grams of acetone. The resulting solution is sprayed at room temperature by means of an atomizer onto a piece of cotton or wool textile and allowed to dry for about two minutes.

A sample of the textile so treated is washed 20 times in a household washing machine with soap or detergent and is then placed on a Petri dish containing agar streaked with a culture of Staphyl coccus aureus. After an incubation period of 24 hours a 2-mm. zone of inhibition is observed.

When the same mixture is sprayed on a piece of commercial air filter, a similar zone of inhibition is found to exist after 20 washings with a commercial detergent.

When a culture of Escherichia Coli is substituted for the Staphylococcus aureus, the zone of inhibition is found to be 3 mm.

3 Example 2 The same as Example 1, except that cyclohexanone is used as a solvent in place of acetone. The solution dries in about five minutes.

A l-mm. zone of inhibition against Staphylococcus aureus is observed after 20 washings.

Example 3 Methyl isobutyl ketone is used as a solvent in lieu of those given in Examples 1 and 2. The drying time is about three minutes. The same zone of inhibition is observed as in Example 2.

It may be mentioned that the concentration of the mixture of the aforedescribed solids in the organic solvent may vary from 0.1% to the saturation point, the latter being approximately 5%.

It should be noted that, especially with the addition of higher percentages of detergent or wetting agent, the composition according to the invention can also be used successfully on synthetic fibers, such as nylon.

Other alkali-metal acetates, such as potassium or 1ithium acetate, may be used as the catalyst in lieu of sodium acetate.

We claim:

1. An antimicrobial treating composition comprising a zinc salt, an aminating agent and a chelating agent all distributed in a volatile organic solvent.

2. A composition according to claim 1 wherein said volatile solvent is a ketone.

3. A composition according to claim 2 including as a catalyst an alkali-metal acetate.

4. A composition according to claim 3 including a detergent.

5. A composition according to claim 3 including a buffering agent.

6. As an article of manufacture, textile fiber impregnated with a composition comprising a zinc salt, an aminating agent and a chelating agent all distributed in a volatile organic solvent.

7. An article of manufacture according to claim 6 wherein the textile fiber is selected from the group consisting of cellulosic, proteinaceous and nylon fibers.

8. An antimicrobial treating composition comprising a zinc salt selected from the group consisting of zinc chloride, zinc sulfate and zinc nitrate; urea; sodium ethylenediamine-tetraacetate and a volatile organic solvent.

9. An antimicrobial treating composition according to claim 8 wherein said volatile organic solvent is a lowboiling ketone.

10. An antimicrobial treating composition according to claim 9 wherein said ketone is selected from the group consisting of acetone and methyl isobutyl ketone.

11. A process for imparting antimicrobial properties to textile fibers comprising applying to said fibers a solution of a zinc salt, an aminating agent and a chelating agent dissolved in a volatile organic solvent and allowing said solution to dry whereby antimicrobial properties are imparted to said textile fibers.

12. A process for imparting antimicrobial properties to textile fibers comprising applying to said fiber a solution of a Zinc salt, a chelating agent dissolved in a volatile organic solvent, treating the fiber with an aminating agent and allowing said fiber to dry whereby antimicrobial prop erties are imparted to said textile fiber.

References Cited in the file of this patent UNITED STATES PATENTS 2,304,478 Rosenzweig Dec. 8, 1942 2,396,514 Kreidl et al. Mar. 12, 1946 2,459,896 Schwarz Jan. 25, 1949 2,459,897 Schwarz Jan. 25, 1949 2,525,049 Signaigo Oct. 10, 1950 2,527,141 Mantell et al. Oct. 24, 1950 2,572,923 Gaver et al. Oct. 30, 1951 2,609,368 Gaver Sept. 2, 1952 2,671,779 Gaver et al. Mar. 9, 1954 2,785,106 Mendelsohn Mar. 12,, 1957 3,004,010 Mendelsohn Oct. 10, 1961 

11. A PROCESS FOR IMPARTING ANTIMICROBIAL PROPERTIES TO TEXTILE FIBERS COMPRISING APPLYING TO SAID FIBERS A SOLUTION OF A ZINC SALT, AND AMINATING AGENT AND A CHELATING AGENT DISSOLVED IN VOLATILE ORGANIC SOLVENT AND ALLOW ING SAID SOLUTION TO DRY WHEREIN ANTIMICROBIAL PROPERTIES ARE IMPARTED TO SAID TEXTILE FIBERS. 